Siloxanes having high refractive index are useful in many applications, including coatings for optical devices, such as contact lenses. Travnicek, U.S. Pat. No. 4,114,993 discloses a method for coating contact lenses comprising applying to the lens a coating of (i) a polymer of a dimethyl siloxane, a diphenyl siloxane or phenyl-methyl siloxane or both, and a vinyl siloxane; (ii) a polymer of a dimethyl siloxane, a diphenyl siloxane or phenyl-methyl siloxane or both, and an alkyl hydrogen siloxane; and (iii) 5 to 20% fume silica.
Other disclosures of silicones for use in optical glass applications, include the Broer et al. patents, U.S. Pat. Nos. 4,718,748 and 4,738,509, which describe an optical glass fiber having a synthetic resin cladding in which the first layer of the synthetic resin cladding is formed from a curable synthetic resin composition comprising a curable polysiloxane composition.
It has now been discovered that a new class of high refractive siloxanes are provided by incorporating aryl-modified siloxy units into a relatively low refractive index phenol-modified siloxane. These novel phenol-modified aryl-modified siloxanes surprisingly exhibit excellent optical properties making them suitable for use in many applications requiring materials having a high refractive index.